'The Hardest Working Water in the World.'

Al Seib / Los Angeles Times

BIG CREEK, CA - JULY 28, 2015: The long cave tunnel that leads to a generator turbine that spins 200 feet beneath Shaver Lake at Southern California Edison's Big Creek John S. Eastwood Power Station which has produced cheap and reliable electricity for decades but now the drought may sideline the station on JULY 28, 2015.

BIG CREEK, CA - JULY 28, 2015: The long cave tunnel that leads to a generator turbine that spins 200 feet beneath Shaver Lake at Southern California Edison's Big Creek John S. Eastwood Power Station which has produced cheap and reliable electricity for decades but now the drought may sideline the station on JULY 28, 2015.

BIG CREEK, CA - JULY 28, 2015: Water flows through Big Creek Power House 1 in Southern California Edison's Big Creek hydro-electric system which serves as the home to one of the largest and most extensive hydroelectric projects in the world. Southern California Edison owns and operates the engineering feat, commonly referred to as the Big Creek Project and dubbed "The Hardest Working Water in the World." Southern California Edison's Big Creek John S. Eastwood Power Station has produced cheap and reliable electricity for decades but now the drought may sideline the station on JULY 28, 2015.

BIG CREEK, CA - JULY 28, 2015: Water flows through Big Creek Power House 1 in Southern California Edison's Big Creek hydro-electric system which serves as the home to one of the largest and most extensive hydroelectric projects in the world. Southern California Edison owns and operates the engineering feat, commonly referred to as the Big Creek Project and dubbed "The Hardest Working Water in the World." Southern California Edison's Big Creek John S. Eastwood Power Station has produced cheap and reliable electricity for decades but now the drought may sideline the station on JULY 28, 2015.